One of the machines I use regularly has a nasty habit of suddenly
locking completely (it happens maybe a couple of times a month). It's
always when X is running, and, I am nearly sure, always when a browser
is being used. This is a Debian testing system, running kernel 2.4.23.
Mozilla-Firefox is the browser that is mostly used.
It's not just that X freezes; the whole system becomes autistic. In
this state, it can't be reached from the network (no ssh, no ping, no
nothing). The only way out, as far as I know, is with the
power-button. Ctl-Alt-Del produces no response. Nor does Alt-SysRq,
which means, I suppose, that the kernel is dead.
These events leave no trace whatever in the logs and so it's
frustratingly hard to do any useful trouble-shooting. I thought that
they might be caused by a corrupt memory-module, and so I ran memtest
for the best part of a day. However it found no errors.
I know that this much doesn't provide a lot of information to go on,
and I apologize for that. But does anyone know of ways to work on a
problem such as this?
I'd be really grateful for any tips or pointers.